The idea behind Tk is to create an easy-to-use interface between Perl and Windows. In order to do this, Tk builds on top of the X Window System (or Microsoft Windows) to create "sub-windows" that contain buttons, menu bars, scroll bars, and other windows components. These components are called widgets .
Widgets are controls that are built into Motif (the heart of the X Window System on UNIX platforms). In fact, you can think of Tk as the process of putting widgets together in an application until you have the graphic interface you need.
